Tonbara
Kume Island's Popular Dive Site: An Ideal Spot for Advanced Divers
Located in Kumejima, Shimajiri, Okinawa Prefecture, Japan, this dive site is highly sought-after by diving enthusiasts. With just a 30-minute flight from Okinawa's main island, you can access this thriving underwater world. A short 20 to 30-minute boat ride from the harbor brings you to a magnificent and rugged rock formation, standing 2 kilometers off the southeast coast of the island.
This renowned spot boasts excellent visibility, reaching up to 26 meters, providing divers with a spectacular view of the marine life. As a tidal passage, it offers a prime opportunity to encounter large fish species. It is particularly famous for being a popular migratory point for hammerhead sharks during the winter months.
Divers who prefer a drift diving experience will find this site particularly appealing. The currents here are known for their complexity and unpredictability, making it an ideal challenge for intermediate and advanced divers. However, due to these challenging conditions, it is recommended that only experienced divers venture into these depths.
Aside from the magnificent hammerhead sharks, this dive site offers another unforgettable experience. During the winter and spring seasons, humpback whales can be observed up close, adding to the excitement and awe-inspiring moments for divers.
Whether you are an expert or an advanced diver, this dive site on Kume Island guarantees an extraordinary adventure in the depths of Japan's waters.
Located in Kumejima, Shimajiri, Okinawa Prefecture, Japan, this dive site is highly sought-after by diving enthusiasts. With just a 30-minute flight from Okinawa's main island, you can access this thriving underwater world. A short 20 to 30-minute boat ride from the harbor brings you to a magnificent and rugged rock formation, standing 2 kilometers off the southeast coast of the island.
This renowned spot boasts excellent visibility, reaching up to 26 meters, providing divers with a spectacular view of the marine life. As a tidal passage, it offers a prime opportunity to encounter large fish species. It is particularly famous for being a popular migratory point for hammerhead sharks during the winter months.
Divers who prefer a drift diving experience will find this site particularly appealing. The currents here are known for their complexity and unpredictability, making it an ideal challenge for intermediate and advanced divers. However, due to these challenging conditions, it is recommended that only experienced divers venture into these depths.
Aside from the magnificent hammerhead sharks, this dive site offers another unforgettable experience. During the winter and spring seasons, humpback whales can be observed up close, adding to the excitement and awe-inspiring moments for divers.
Whether you are an expert or an advanced diver, this dive site on Kume Island guarantees an extraordinary adventure in the depths of Japan's waters.
Diving Conditions Score for Tonbara
8.3
Very GoodVery good diving conditions!
The score is based on a calculation of the current weather and sea conditions.
Dive Site Overview for Tonbara
Depth
19m
Visibility
26m
Experience Level
advanced
expert
Weather Conditions for Tonbara
Wave Height
0.84m
Wind Speed
11 m/s
Water Temp
26.6°C
Visibility
20.54km
Cloud Cover
30%
Wave Period
9s
Air Temperature
26.6°C
Precipitation
0 mm
Detailed 7-Day Diving Forecast for Tonbara
Alpha
Dive Score Chart for Tonbara
Best time to dive: 12:00 with score 8.40955135135135/10. Water conditions: Waves 0.72m, Wind 12.8 m/s.Best night dive time: 20:00 with score 7.891148802946593/10.
Chart showing hourly dive conditions including wave height, wind speed, water temperature, and visibility throughout the day.
Sunrise at Tonbara: 06:00
Sunset at Tonbara: 18:00
Optimal diving conditions at Tonbara are affected by daylight hours. Sunrise occurs at 06:00 and sunset at 18:00, which impacts visibility and water temperature for scuba diving and snorkeling.
Best Overall
12:00Score: 8.4/10
Waves: 0.72m (7.4s), Wind: 12.8 m/s
Best Night
20:00Score: 7.9/10
Waves: 0.84m, Wind: 11.4 m/s
Seasonal Analysis for TonbaraAlpha
Historical patterns and best seasons for diving at Tonbara
The dive score combines all factors to rate overall diving conditions throughout the year. Higher scores indicate better diving conditions.
Monthly Dive Score Analysis - Seasonal Diving Conditions
Higher values indicate better diving conditions
Seasonal DiveScore Chart
This chart displays monthly diveScore data throughout the year, showing seasonal patterns. The data is presented as a bar chart with an overlaid line graph.Dive scores range from 1 to 10, with 10 being optimal conditions.
Higher values indicate better diving conditions
Best Season for Tonbara
Winter
Avg. Score: 8.4/10
Winter offers the best overall diving conditions with calmer seas and better visibility, despite cooler temperatures.
Best Months for Tonbara
January
Score: 8.5
November
Score: 8.4
December
Score: 8.4
Ideal Conditions for Tonbara
Water Temp
27.0°C / 80.6°F
June
Visibility
11.7m / 38.4ft
August
Wave Height
2.8m / 9.2ft
August
Wave Period
8.0s
January
Seasonal Insights for Tonbara
Tonbara shows typical northern hemisphere patterns with July being the warmest month (28.8°C) and January the coldest (15.1°C). The calmest conditions typically occur in August with average wave heights of 2.8m and wave periods of 8.0s. The most comfortable wave conditions are in August with a low wave steepness ratio, creating gentler swells. January offers the longest wave periods (8.0s), creating more comfortable and predictable conditions for boat entries and exits. Ocean currents are slowest in January (0.5m/s) and strongest in January (0.5m/s). March is usually the driest month with 0.2mm of precipitation. For beginners, the best time to visit would be during August to October, when ocean conditions are calmer with long-period waves and currents are typically weaker. Experienced divers might enjoy the challenges and potentially better visibility during the shoulder seasons, with moderate currents that can improve marine life encounters.
Last updated: 1 min. ago - Jun 21, 2026
Note: This dive site is not a verified dive site. Please dive with caution. This dive site might have incorrect information by the community.
6 Dive sites near Tonbara in
Got feedback?
Help us improve this dive site by giving us feedback.